The rule
From Apple’s submission page: “Starting April 2027, apps and games uploaded to App Store Connect need to meet the following minimum requirements.” For iPhone and iPad apps, that means built with the iOS & iPadOS 27 SDK or later, and targeting iOS 15 or later. The rule in place since 28 April 2026 is the iOS 26 SDK.
Who it affects
Apps already on the App Store stay there: the rule applies to uploads. But the next update, even a one-line fix, has to meet it. That is usually when an old app turns out not to build any more.
What can change when you rebuild
- The minimum iOS version. An app that still supports iOS 14 or earlier has to raise its deployment target to iOS 15, and people on older versions stop receiving updates.
- How standard screens look. A new SDK can change the appearance and behaviour of system components without a line of your code changing. Check every main screen before you submit.
- iPhone Duo. Apps built with the iOS 27 SDK resize to fill most of iPhone Duo’s inner display; with 27.1 or later they use all of it, with toolbars and tab bars on the side. A layout that assumes a fixed screen size will show it. See what to do about iPhone Duo now.
- Dependencies. Third-party libraries and SDKs have to work with the new Xcode too. Old, unmaintained ones are often what turns a rebuild from hours into weeks.
- In-app purchases. If the app still uses the original StoreKit API, this is a good moment to move to StoreKit 2, which Apple names as the requirement for the new subscription features in iOS 27.
A plan
- Open the project in Xcode 27 now, and see whether it builds.
- List the dependencies that block the build, and the ones with no recent release.
- Raise the deployment target to iOS 15 if needed, and remove code for older versions.
- Test every main screen, including in the iPhone Duo simulator.
- Release the rebuilt app well before April, so the deadline never decides when you can fix a bug.
If the team that built your app has moved on, a short review is the cheapest way to find out where you stand. Our guide to iOS app maintenance explains what that involves.
Sources: Apple’s Submitting page and App Store submissions now open for the latest OS releases, 9 September 2026.
Related: iOS app maintenance cost · What’s new in iOS 27 · iPhone Duo: how to get your app ready